The present invention relates chiefly to a stopper apparatus for the inner member used in a tripod type sliding universal joint which is applied mainly to automobiles.
A conventional universal joint, as disclosed in U.S. Pat. No. 3,613,396, has a structure in which a stopper d is rigidly secured to the end wall b of an inner member accommodating chamber formed in an outer member a, the stopper d being there to receive the end surface of the inner member c which is urged toward the end wall b, as shown in FIG. 1.
Generally, the end surface of the inner member c of a tripod type sliding universal joint is formed as a spherical shape which has its center at an intersecting point O at which the axis A of the inner member c intersects the axis B of a radially projecting portion of the inner member c. The surface of the stopper d that receives the end surface of the inner member c is formed as a correspondingly recessed spherical surface for engagement. When power transmission is performed through the outer member a and the inner member c which are engaged with each other in such a manner that their axes A and D obliquely intersect each other, the intersecting point O deviates from the axis D of the outer member a, this deviation being the so-called center deviation of the inner member c whose magnitude is determined by the angle formed between the axes of the two members a and c. This causes the end surface of the inner member c to have only a partial contact with the stopper, resulting in an unsymmetrical wear of the inner member c.